K. Brendel et al., PROXIMAL RENAL TUBULE PREPARATIONS ISOLATED FROM RAT OR RABBIT KIDNEYS WITHOUT THE USE OF COLLAGENASE, Toxicology methods, 3(2), 1993, pp. 87-99
Kidney tubules have previously been isolated from a number of differen
t animal species using techniques involving perfusion and digestion of
the organ with collagenase, followed by centrifugation of the resulti
ng suspension. These techniques suffer from the disadvantages of requi
ring prolonged incubation with a potentially damaging enzyme and conta
mination of the preparations with glomeruli. We have developed a proce
dure for the isolation of a purified preparation of rabbit kidney tubu
les without collagenase digestion. Rabbit or rat kidneys are perfused
with buffer, followed by a suspension of magnetic iron oxide. The cort
ex is then homogenized by hand and put through nylon sieves of varying
mesh sizes that separate large pieces of tissue from the glomeruli an
d tubules, which are caught on the smaller mesh sieves. The glomeruli
containing entrapped iron oxide are then separated from the tubules wi
th the aid of a magnet. Tubules isolated in this way are morphological
ly intact as shown by electron microscopy and have intact basement mem
branes in contrast to those isolated with the use of collagenase treat
ment. These tubules are equal to or surpass those isolated with the us
e of collagenase in metabolic functions such as oxidative metabolism a
nd gluconeogenesis and in transport functions such as PAH and 2-deoxyg
lucose uptake.